# coding=utf-8
# __author__ = 'chenbinghui'
#!/usr/bin/python
# -*- coding: UTF-8 -*-
import urllib2
import urllib
import re

#处理页面标签类
class Tool:
    #去除img标签,7位长空格
    removeImg = re.compile('<img.*?>| {7}|')
    #删除超链接标签
    removeAddr = re.compile('<a.*?>|</a>')
    #把换行的标签换为\n
    replaceLine = re.compile('<tr>|<div>|</div>|</p>')
    #将表格制表<td>替换为\t
    replaceTD= re.compile('<td>')
    #把段落开头换为\n加空两格
    replacePara = re.compile('<p.*?>')
    #将换行符或双换行符替换为\n
    replaceBR = re.compile('<br><br>|<br>')
    #将其余标签剔除
    removeExtraTag = re.compile('<.*?>')
    def replace(self,x):
        x = re.sub(self.removeImg,"",x)
        x = re.sub(self.removeAddr,"",x)
        x = re.sub(self.replaceLine,"\n",x)
        x = re.sub(self.replaceTD,"\t",x)
        x = re.sub(self.replacePara,"\n    ",x)
        x = re.sub(self.replaceBR,"\n",x)
        x = re.sub(self.removeExtraTag,"",x)
        #strip()将前后多余内容删除
        return x.strip()

#百度贴吧爬虫类
class BDTB_Crawler:
    #初始化，传入基地址，是否只看楼主的参数
    def __init__(self,baseUrl,seeLZ,floorTag):
        self.baseUrl = baseUrl
        self.seeLZ = '?see_lz='+str(seeLZ)
        self.user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'
        self.headers = {'User-Agent': self.user_agent}
        self.tool = Tool()
        #全局file变量
        self.file = None
        #初始化楼层
        self.floor = 1
        #默认的标题
        self.defaultTitle = u'百度贴吧'
        #是否写入楼层的分隔符
        self.floorTag = floorTag
    #传入页码，获取该页帖子的代码
    def getPage(self,pageNum):
        try:
            url = self.baseUrl + self.seeLZ + '&pn=' + str(pageNum)
            request = urllib2.Request(url,headers=self.headers)
            response = urllib2.urlopen(request)
            pageCode = response.read().decode('utf-8')
            #print pageCode
            return pageCode
        except urllib2.URLError,e:
            if hasattr(e,'reason'):
                print u'连接百度贴吧失败，错误原因',e.reason
                return None

    #获取帖子标题，需要准确定位
    def getTitle(self):
        page = self.getPage(1)
        pattern = re.compile('<h3 class="core_title_txt.*?>(.*?)</h3>',re.S)
        result = re.search(pattern,page)
        if result:
            # print result.group(1)
            return result.group(1).strip()
        else:
            return None
    #获取帖子的页数
    def getPageNum(self):
        page = self.getPage(1)
        pattern = re.compile('<li class="l_reply_num.*?<span class="red">(.*?)</span>',re.S)
        result = re.search(pattern,page)
        if result:
            print result.group(1)
            return result.group(1).strip()
        else:
            return None
    #获取每一层楼的内容，传入页面内容
    def getContent(self,page):
        pattern = re.compile('<div id="post_content_.*?>(.*?)</div>',re.S)
        items = re.findall(pattern,page)
        contents = []
        for item in items:
            content = '\n'+self.tool.replace(item)+'\n'
            contents.append(content.encode('utf-8'))
        return contents
    #写入文件中
    def writeData(self,contents):
        for item in contents:
            if self.floorTag =='1':
                floorLine = '\n'+str(self.floor)+u"--------------------------------------\n"
                self.file.write(floorLine)
            self.file.write(item)
            self.floor += 1

    #写入标题文件
    def setFileTitle(self,title):
        if title is not None:
            self.file = open(title +'.txt','w+')
        else:
            self.file = open(self.defaultTitle+'.txt','w+')

    #开始入口
    def start(self):
        indexPage = self.getPage(1)
        pageNum = self.getPageNum()
        title = self.getTitle()
        self.setFileTitle(title)
        if pageNum == None:
            print 'URL已失效，请重试'
            return
        try:
            print "该帖子共有"+str(pageNum)+"页"
            for i in range(1,int(pageNum)+1):
                print "正在写入第"+str(i)+"页数据"
                page = self.getPage(i)
                contents =self.getContent(page)
                self.writeData(contents)
        except IOError,e:
            print "写入异常，原因"+e.message
        finally:
            print "写入任务完成"


# baseUrl = 'https://tieba.baidu.com/p/3138733512'
# bdtb = BDTB_Crawler(baseUrl,1,1)
# bdtb.start()
print u'请输入帖子代号'
baseUrl ='http://tieba.baidu.com/p/'+str(raw_input(u'http://tieba.baidu.com/p/'))
seeLZ= raw_input('是否只看楼主发言，是输入1，否输入0\n')
floorTag = raw_input('是否写入楼层信息，是输入1，否输入0\n')
bdtb = BDTB_Crawler(baseUrl,seeLZ,floorTag)
bdtb.start()
